;
; Graphics driver for the 240x200x2 monochrome mode on the Atmos
;
; Jede (jede@oric.org), 2017-10-15


        .include        "zeropage.inc"

        .include        "tgi-kernel.inc"
        .include        "tgi-error.inc"
        .include        "telestrat.inc"

        .macpack        generic
        .macpack        module

XSIZE   =       6                       ; System font width
YSIZE   =       8                       ; System font height

; ------------------------------------------------------------------------
; Header. Includes jump table and constants.

        module_header   _telestrat_240_200_2_tgi

; First part of the header is a structure that has a magic and defines the
; capabilities of the driver

        .byte   $74, $67, $69           ; "tgi"
        .byte   TGI_API_VERSION         ; TGI API version number
        .addr   $0000                   ; Library reference
        .word   240                     ; X resolution
        .word   200                     ; Y resolution
        .byte   2                       ; Number of drawing colors
        .byte   1                       ; Number of screens available
        .byte   XSIZE                   ; System font X size
        .byte   YSIZE                   ; System font Y size
        .word   $011C                   ; Aspect ratio (based on 4/3 display)
        .byte   0                       ; TGI driver flags

; Next comes the jump table. Currently all entries must be valid and may point
; to an RTS for test versions (function not implemented).

        .addr   INSTALL
        .addr   UNINSTALL
        .addr   INIT
        .addr   DONE
        .addr   GETERROR
        .addr   CONTROL
        .addr   CLEAR
        .addr   SETVIEWPAGE
        .addr   SETDRAWPAGE
        .addr   SETCOLOR
        .addr   SETPALETTE
        .addr   GETPALETTE
        .addr   GETDEFPALETTE
        .addr   SETPIXEL
        .addr   GETPIXEL
        .addr   LINE
        .addr   BAR
        .addr   TEXTSTYLE
        .addr   OUTTEXT

; ------------------------------------------------------------------------
; Data.

; Variables mapped to the zero page segment variables. Some of these are
; used for passing parameters to the driver.

X1              := ptr1
Y1              := ptr2
X2              := ptr3
Y2              := ptr4

; Absolute variables used in the code

.bss

ERROR:          .res    1       ; Error code
MODE:           .res    1       ; Graphics mode

; Constant table

.rodata

DEFPALETTE:     .byte   0, 1

.code

; ------------------------------------------------------------------------
; INSTALL routine. Is called after the driver is loaded into memory. May
; initialize anything that has to be done just once. Is probably empty
; most of the time.
;
; Must set an error code: NO
;

INSTALL:

; ------------------------------------------------------------------------
; UNINSTALL routine. Is called before the driver is removed from memory. May
; clean up anything done by INSTALL but is probably empty most of the time.
;
; Must set an error code: NO
;

UNINSTALL:
        rts

; ------------------------------------------------------------------------
; INIT: Changes an already installed device from text mode to graphics
; mode.
; Note that INIT/DONE may be called multiple times while the driver
; is loaded, while INSTALL is only called once, so any code that is needed
; to initializes variables and so on must go here. Setting palette and
; clearing the screen is not needed because this is called by the graphics
; kernel later.
; The graphics kernel will never call INIT when a graphics mode is already
; active, so there is no need to protect against that.
;
; Must set an error code: YES
;

INIT:

; Switch into graphics mode

        BRK_TELEMON(XHIRES)

; Done, reset the error code

        lda     #TGI_ERR_OK
        sta     ERROR
        rts

; ------------------------------------------------------------------------
; DONE: Will be called to switch the graphics device back into text mode.
; The graphics kernel will never call DONE when no graphics mode is active,
; so there is no need to protect against that.
;
; Must set an error code: NO
;

DONE:
        BRK_TELEMON(XTEXT)
        rts

; ------------------------------------------------------------------------
; GETERROR: Return the error code in A and clear it.

GETERROR:
        ldx     #TGI_ERR_OK
        lda     ERROR
        stx     ERROR
        rts

; ------------------------------------------------------------------------
; CONTROL: Platform/driver specific entry point.
;
; Must set an error code: YES
;

CONTROL:
        ; not done yet
        rts

; ------------------------------------------------------------------------
; CLEAR: Clears the screen.
;
; Must set an error code: NO
;

CLEAR:
        BRK_TELEMON(XEFFHI)
        rts

; ------------------------------------------------------------------------
; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
; The page number is already checked to be valid by the graphics kernel.
;
; Must set an error code: NO (will only be called if page ok)
;

SETVIEWPAGE:

; ------------------------------------------------------------------------
; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
; The page number is already checked to be valid by the graphics kernel.
;
; Must set an error code: NO (will only be called if page ok)
;

SETDRAWPAGE:
        rts

; ------------------------------------------------------------------------
; SETCOLOR: Set the drawing color (in A). The new color is already checked
; to be in a valid range (0..maxcolor-1).
;
; Must set an error code: NO (will only be called if color ok)
;

SETCOLOR:
        ;not done yet
        rts

; ------------------------------------------------------------------------
; SETPALETTE: Set the palette (not available with all drivers/hardware).
; A pointer to the palette is passed in ptr1. Must set an error if palettes
; are not supported
;
; Must set an error code: YES
;

SETPALETTE:
        lda     #TGI_ERR_INV_FUNC       ; This resolution has no palette
        sta     ERROR
        rts

; ------------------------------------------------------------------------
; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
; set the palette should return the default palette here, so there's no
; way for this function to fail.
;
; Must set an error code: NO
;

GETPALETTE:

; ------------------------------------------------------------------------
; GETDEFPALETTE: Return the default palette for the driver in A/X. All
; drivers should return something reasonable here, even drivers that don't
; support palettes, otherwise the caller has no way to determine the colors
; of the (not changeable) palette.
;
; Must set an error code: NO (all drivers must have a default palette)
;

GETDEFPALETTE:
        ; not done yet
        rts

; ------------------------------------------------------------------------
; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
; color. The coordinates passed to this function are never outside the
; visible screen area, so there is no need for clipping inside this function.
;
; Must set an error code: NO
;

SETPIXEL:
        lda #$80       ; curset on
SETPIXELSETMODE:
        sta HRSFB

        lda X1
        sta HRS1
        lda Y1
        sta HRS2



        BRK_TELEMON(XCURSE)

        rts

; ------------------------------------------------------------------------
; GETPIXEL: Read the color value of a pixel and return it in A/X. The
; coordinates passed to this function are never outside the visible screen
; area, so there is no need for clipping inside this function.

GETPIXEL:
        ; not done yet
        rts

; ------------------------------------------------------------------------
; LINE: Draw a line from X1/Y1 to X2/Y2, where X1/Y1 = ptr1/ptr2 and
; X2/Y2 = ptr3/ptr4 using the current drawing color.
;
; Must set an error code: NO
;

LINE:

        lda   X1
        sta   HRS1
        lda   Y1
        sta   HRS2

        lda   X2
        sta   HRS3
        lda   Y2
        sta   HRS4


        lda   X1+1
        sta   HRS1+1

        lda   Y1+1
        sta   HRS2+1

        lda   X2+1
        sta   HRS3+1

        lda   Y2+1
        sta   HRS4+1

        lda   #$FF
        sta   HRSPAT

        BRK_TELEMON(XDRAWA)

        rts

CIRCLE:
        ; not done yet
        rts

; ------------------------------------------------------------------------
; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
; Contrary to most other functions, the graphics kernel will sort and clip
; the coordinates before calling the driver, so on entry the following
; conditions are valid:
;       X1 <= X2
;       Y1 <= Y2
;       (X1 >= 0) && (X1 < XRES)
;       (X2 >= 0) && (X2 < XRES)
;       (Y1 >= 0) && (Y1 < YRES)
;       (Y2 >= 0) && (Y2 < YRES)
;
; Must set an error code: NO
;

BAR:
        ; not done yet
        rts

; ------------------------------------------------------------------------
; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
; direction is passend in X/Y, the text direction is passed in A.
;
; Must set an error code: NO
;

TEXTSTYLE:
        rts


; ------------------------------------------------------------------------
; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
; current text style. The text to output is given as a zero terminated
; string with address in ptr3.
;
; Must set an error code: NO
;

OUTTEXT:
        ; put hires cursor in X & Y
        lda   #$00
        jsr   SETPIXELSETMODE


        ; count the length of the string
        ldy   #$00
loop:
        lda   (ptr3),y
        beq   out
        iny
        bne   loop
out:
        ; XSCHAR routine from telemon needs to have the length of the string in X register
        ; copy Y register to X register. It could be optimized in 65C02 with TYX
        tya
        tax

        lda   ptr3     ; XSCHAR needs in A and Y the address of the string
        ldy   ptr3+1
        BRK_TELEMON(XSCHAR)
        rts
